Abstract: A chain saw hazard warning light and method for using same. A pair of oppositely-directed light sources emit light beams throughout a chain shot hazard warning zone through rectilinear, slotted openings at opposite ends of a housing. The light beams turn on, if and only if, the cutting chain is rotating about the chain guide bar; alternatively, initiation of rotation of the cutting chain is delayed to permit the light beams to turn on some time prior thereto. The zone is defined by first and second pairs of planes that diverge in opposite directions from the chain guide bar, said planes being disposed at equal, acute angles (most preferably 15°) to, and on opposite sides of, a plane that includes the chain guide bar.

Abstract: A timber-working head and method of operation are provided. The head has a frame to which first and second arms are pivotally connected. Respective linear drive actuators pivot the respective arms relative to the frame to open and close them. At least one processor controls application of pressure by the linear drive actuators such that the arms grasp timber to be processed by the head. The position of the linear actuators is used to determine whether the timber is offset from a feed axis of the frame beyond a predetermined distance, and the application of pressure by one of the linear actuators to reduce the offset to be within the predetermined distance.

Abstract: A method, apparatus, and system for operation of a timber-working device capable of performing an operation having an associated hazard zone. The device can receive a wireless signal indicating a location of an object tracking device, determine the location of the object tracking device relative to the hazard zone of the timber-working device and determine a recommended operation of the timber-working device based at least in part on the location of the object tracking device relative to the hazard zone.

Abstract: Method, apparatus, and system for operation of a timber-working device configured to perform at least one operation having an associated hazard zone. At least one signal from at least one orientation sensor associated with the timber-working head may indicate whether a predetermined location is within the hazard zone based on the orientation of the timber-working head. Operation of the timber-working head can be controlled based on the signal.

Abstract: A power tool comprises a base unit and a motor unit. The base unit includes a handle and a first electrical connector. The motor unit includes an electric motor and a second electrical connector. The motor unit is configured to be releasably connected to the base unit. An electrical connection is established between the first electrical connector and the second electrical connector when the motor unit is properly connected to the base unit. A sensor is configured to determine whether the motor unit is properly connected to the base unit.

Abstract: A machine is described having at least one dangerous portion. The machine also includes a safety system to detect dangerous proximity between a person and the dangerous portion and perform a predetermined action to limit or prevent injury to the person from the dangerous portion. The machine may include high voltage generation means, connection means, and electronic detection means.

Abstract: A table saw includes a curved channel formed in a supporting base, a cradle attached to the supporting base, an arbor bracket attached to the cradle for supporting a saw blade and a motor, a height shaft attached to the cradle and extended through the curved channel of the base for engaging with the arbor bracket, a tilt shaft attached to the base and engaged with the cradle for adjusting the saw blade relative to the base to selected angular positions, a follower slidably engaged in the curved channel of the base, and a signal generating device attached to the follower for detecting a bevel angle of the arbor bracket and the cradle and the saw blade relative to the base and for precisely showing the angle with digits.

Abstract: Methods to detect when a human body contacts a predetermined portion of a machine are disclosed. The methods distinguish contact with a person from contact with other materials. The methods are particularly applicable in woodworking equipment such as table saws to distinguish contact between a person and the blade of the saw from contact between the blade and wet or green wood. The methods and woodworking equipment may include predictive blade stop algorithms that prevent unnecessary activations of a safety brake during coast down of a blade and continued protection in the event a main power switch is turned off.

Abstract: A light source is used to illuminate a sawn portion of a piece of wood and exposed surfaces of the saw blade on both sides of the sawn portion. The sawn portion and the exposed surfaces of the saw blade are then imaged substantially concurrently using a single image generator. At least one geometric characteristic of the sawn portion and at least one geometric characteristic of the saw blade are determined based on the imaging.